EP-A-268498 describes a water-absorbent water-insoluble polymeric fibre, film, coating, bonding layer or foam, made by forming a substantially linear polymer by polymerisation of water-soluble ethylenically unsaturated monomer blends comprising carboxylic and hydroxylic monomers and then reacting the carboxylic and hydroxylic monomers in the linear polymer to form internal crosslinks within the polymer.
EP-A-269393 describes a water-absorbent water-insoluble crosslinked polymer fibre or film made by dry extrusion of a solution of a substantially linear polymer formed from a water-soluble blend of monoethylenically unsaturated monomers comprising a plasticising monomer, evaporating the solvent and forming polymeric fibre or film plasticised by an external plasticiser, stretching the fibre or film while the external plasticiser remains in the fibre or film, and then crosslinking the polymer.
EP-A-342919 describes film or fibre made by extrusion and stretching from a polymer of water-soluble ethylenically unsaturated monomers that include ionic monomer. A counterionic lubricant compound is absorbed into the surface of the fibre or film before or during the stretching.
EP-A-397410 describes a water-soluble linear polymer of carboxylic acid monomers such as acrylic acid and a hydroxylic monomer which can be crosslinked, after being shaped by extrusion of an aqueous solution of the polymer as fibre or film, to form crosslinks between the carboxyl and hydroxyl groups.
FR-A-2355929 describes a process for manufacturing yarns and fibres having a water-retention capacity of more than 80% by weight, in which process aqueous solutions containing water-soluble polymers of acrylic acid, distributed homogeneously, and aliphatic, cycloaliphatic, araliphatic or aromatic compounds that contain at least two hydroxyl and/or primary or secondary amino groups in their molecule are spun, and the yarns spun in this way are heated at temperatures of between 100.degree. and 200.degree. C.